The present invention relates to a machine-readable indelible identifying mark on a storage media More particularly, the present invention relates to such an indelible mark ablated or otherwise imprinted into a storage media such as a magnetic storage media, wherein the mark is read by detecting the absence of portions of such media.
As part of the present invention, the inventors thereof have discovered that it is highly useful to indelibly mark or identify a storage media, such that the marking identification cannot be modified, removed, or otherwise altered, and such that the mark can be relatively easily read. Such an identification can for example be unique or non-unique, and can for example signify that the media is read-only, write-once, has some other specific characteristic, or the like. Additionally, the identification may signify that the media is from a specific vendor, for a specific type of drive or device, for use with a specific vendor""s software or firmware, or the like.
Moreover, such identification may signify that the media has a pre-defined disk storage capacity, a pre-defined purpose, or contains a pre-determined type of application. Further, the mark may signify a security key or a portion thereof which in combination with another portion obtained elsewhere allows access to the information on the media. In short, such identification may have any identifying purpose while still being within the spirit and scope of the present invention as described below.
One way to create such an identification on such storage media is to construct an identification file and store such file on the media. However, and as should be understood, such an identification is easily alterable simply by accessing and modifying the identification file with readily available reading/writing equipment.
Another way to create such an identification on such storage media is to print, stamp, or otherwise create an identifying mark on a sleeve or cartridge or the like within which the media resides. However, such identifying mark may likewise be altered, by replacing the sleeve or cartridge or the like. Moreover, such an identifying mark is not preferred because the drive reading the media likely requires additional hardware specifically for reading the identifying mark on such sleeve or cartridge or the like.
Accordingly, a need exists for an identifying mark that is formed inseparably from the media, where such mark cannot be altered. Moreover, a need exists for such an identifying mark that is formed on the media itself, where a drive reading the media need not require additional hardware specifically for reading such mark.
The present invention satisfies the aforementioned need by providing a storage media comprising a storage body and a readable indelible mark formed in the body such that portions thereof are indelibly altered. The mark is read by writing first data to the body in the region of the mark, and reading second data from the body in such region. The written first data is not accepted where the portions of the body are indelibly altered. Accordingly, the read second data corresponds to the written first data with segments thereof missing. The missing segments of the first data correspond to the portions of the body indelibly altered.
In one embodiment of the present invention, the storage media comprises a magnetic rotatable disk having a substantially planar substrate and a magnetizable layer deposited thereon. The reading and writing are therefore performed magnetically.